spring的JavaConfig方式及xml配置文件混用的例子

文件結構

1、interface、bean等代碼

package com.yiibai.core;

public interface IHelloWorld {
	public void printHello();
	void printHelloWorld(String msg);
}

package com.yiibai.core;

public class HelloWorldImpl implements IHelloWorld {
	private String name;

	@Override
	public void printHello() {
		// TODO 自動生成的方法存根
		System.out.println("Spring 3 : Hello ! " + name);
	}

	public void setName(String name) {
		this.name = name;
	}

	@Override
	public void printHelloWorld(String msg) {
		// TODO 自動生成的方法存根
		System.out.println("Hello : " + msg);
	}


}

package com.yiibai.core;

public class CustomerBo {
	public void printMsg(String msg) {

		System.out.println("CustomerBo : " + msg);
	}
}

package com.yiibai.core;

public class SchedulerBo {
	public void printMsg(String msg) {

		System.out.println("SchedulerBo : " + msg);
	}
}

2、AppConfig(至關於配置文件)

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.yiibai.core.CustomerBo;

@Configuration
public class CustomerConfig {
	
	@Bean(name="customer")
	public CustomerBo customerBo(){
		
		return new CustomerBo();
		
	}
}

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.yiibai.core.SchedulerBo;

@Configuration
public class SchedulerConfig {
	
	@Bean(name="scheduler")
	public SchedulerBo suchedulerBo(){
		
		return new SchedulerBo();
		
	}
	
}

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;

import com.yiibai.core.HelloWorldImpl;
import com.yiibai.core.IHelloWorld;

@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
	
    @Bean(name="helloBean")
    public IHelloWorld helloWorld() {
        return new HelloWorldImpl();
    }
	
}

3、測試（主類）

package com.yiibai.config;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.yiibai.core.CustomerBo;
import com.yiibai.core.IHelloWorld;
import com.yiibai.core.SchedulerBo;

public class App {

	private static ApplicationContext context;

	public static void main(String[] args) {
		context = new AnnotationConfigApplicationContext(AppConfig.class);
        IHelloWorld obj = (IHelloWorld) context.getBean("helloBean");
    
    obj.printHelloWorld("Spring Java Config");

	CustomerBo customer = (CustomerBo) context.getBean("customer");
	customer.printMsg("Hello 11");

	SchedulerBo scheduler = (SchedulerBo) context.getBean("scheduler");
	scheduler.printMsg("Hello 22");
	}

}

4、運行

5、set函數注入bean屬性的狀況：

AppConfig類內增長下面的代碼：

@Bean(name="helloBean1")
    public IHelloWorld helloWorld1() {
       HelloWorldImpl myhello= new HelloWorldImpl();
       myhello.setName("Yiibai");
       return myhello; 
    }

等價於如下的XML配置：

<bean id="helloBean1" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>

 

6、無xml配置AOP

兩點：

一、AOP類加上下面的註釋

@Component
@Aspect

增長AOP類---AopConfig內容以下：

package com.yiibai.config;

import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Component
@Aspect
public class AopConfig {
	/*Pointcut for printMsg*/
	@Pointcut("execution(* *.printMsg(*))")
	public void printpoint() {
	}
	
	@Before("printpoint()")
	public void beforepoint() {
		System.out.println("接下去調用printMsg()......");
	}
	
	@AfterReturning("printpoint()")
	public void afterprint() {
		System.out.println("函數printMsg()執行結束......");
	}
}

二、JavaConfig類加上：

@ComponentScan
@EnableAspectJAutoProxy

修改後的JavaConfig類---AppConfig代碼以下：

package com.yiibai.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.context.annotation.Import;
import com.yiibai.core.HelloWorldImpl;
import com.yiibai.core.IHelloWorld;

@Configuration
@ComponentScan
@EnableAspectJAutoProxy 
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {
	
    @Bean(name="helloBean")
    public IHelloWorld helloWorld() {
        return new HelloWorldImpl();
    }
	
}

運行：

7、混用XML與Java裝配方式

包com.yiibai.config下建立配置文件applicationContext.xml（本人習慣把配置文件放在包裏，這樣便於隨包總體轉移到其餘項目而沒必要修改代碼）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">

	<bean id="helloBean" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>

</beans>

用來註冊helloBean。

對AppConfig以下修改：

1）@Configuration前加上@ImportResource("classpath:com/yiibai/core/applicationContext.xml")

2）註釋helloBean的內容。

修改好的內容：

package com.yiibai.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.ImportResource;

@ImportResource("classpath:com/yiibai/core/applicationContext.xml")
@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {

}

測試代碼和運行結果都不變

（也不是徹底不變，會多出一條相似以下的消息

2017-10-10 22:45:49 [org.springframework.beans.factory.xml.XmlBeanDefinitionReader]-[INFO] Loading XML bean definitions from class path resource [com/yiibai/core/applicationContext.xml]
）

如須要在xml配置AOP，則applicationContext.xml內容以下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
                         http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
                         http://www.springframework.org/schema/context
                         http://www.springframework.org/schema/context/spring-context-4.3.xsd
                         http://www.springframework.org/schema/tx
                         http://www.springframework.org/schema/tx/spring-tx-4.3.xsd
                         http://www.springframework.org/schema/aop 
                         http://www.springframework.org/schema/aop/spring-aop-4.3.xsd ">
	<context:annotation-config />	
	 <aop:aspectj-autoproxy />
	
	<bean id="helloBean" class="com.yiibai.core.HelloWorldImpl">
		<property name="name" value="Yiibai" />
	</bean>
	
	<!--定義切面 -->
	<bean id="aopConfig" class="com.yiibai.config.AopConfig" />

</beans>

類方式注入使用aop需將<aop:aspectj-autoproxy> 改成<aop:aspectj-autoproxy proxy-target-class="true"/> 或 <aop:config proxy-target-class="true"> </aop:config>,不然會出現cannot be cast to .......錯誤.

7、注意：Web環境中使用JavaConfig，須要在web.xml中加入以下代碼：

<context-param>  
    <param-name>contextClass</param-name>  
    <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>  
</context-param>  
<context-param>  
    <param-name>contextConfigLocation</param-name>  
    <param-value>com.packtpub.learnvaadin.springintegration.SpringIntegrationConfiguration</param-value>  
</context-param>

 

參考：

Spring進行面向切面編程的一個簡單例子 

史上最全最強SpringMVC詳細示例實戰教程

Spring JavaConfig實例

Spring @Configuration使用

使用@Configuration註解來代替Spring的bean配置